Jim Keeler was pushing (maybe exceeding) the limits of what could/couldn't be done then. Supposedly he had Tom West design the parts under the pretense that the series would all be 1/8 scale, then halved everything. The engines are beautiful, but probably overkill. Revell seems to have gotten it right, their kits were buildable even for drag race fans that didn't necessarily build model cars all the time, or had graduated to wrenching 1:1 stuff. Maybe had both companies not jumped in at the same time, Aurora would have fared better?
--Mark